Nick Clegg has thwarted plans by the education secretary, Michael Gove, to allow the new generation of "free schools" to make profits in the state sector after a massive ideological battle over the coalition's education policy.
The deputy prime minister will on Monday trumpet his success as one of three key victories achieved over Gove, which he says will ensure that free schools have to operate for the "whole community" and not just for "the privileged few" or for profit.
Sources close to Gove admitted last night that the education secretary had been hoping to allow free schools, which are set up by local people but still funded by the state, to make profits in the second term of a Tory-led government.
A Gove supporter said: "Gove has never had an ideological issue with profit in schools, whereas Clegg is ruling it out for ideological reasons."
Previously the Tories have denied that they were planning to allow profits to be made within the state sector by businesses taking over the schools. The admission comes as the first batch of 24 free schools open their doors this week with pupils returning from holiday.
Clegg's aides say he has also persuaded Gove to amend the admissions code from 2013 to allow free schools and academies to give priority to pupils from disadvantaged backgrounds (those on free school meals). Free schools and academies will be expected to do all they can to ensure that, as a minimum, they have the same amount of pupils on free school meals as the local average.
In a third move, Clegg has won a guarantee from Gove that all of the free schools set up in the next wave will either be in deprived areas or areas in need of more places. Many of the schools in the first wave are being set up in middle-class areas where critics say there is no proven need for extra places. This, opponents say, could mean more resources going to already well-served areas and less to regions in need.
In a speech to teachers, parents and students, Clegg will say he is in favour of free schools, but will add: "I want them to be available to the whole community – open to all children and not just the privileged few. I want them to be part of a school system that releases opportunity, rather than entrenching it.
"They must not be the preserve of the privileged few, creaming off the best pupils while leaving the rest to fend for themselves, causing problems for and draining resources from other nearby schools. So let me give you my assurance: I would never tolerate that."
Clegg feared that his claims to be advancing the cause of social mobility in government would be called into question unless he put his stamp on the Gove plans. He will add: "The coalition has made it clear that our overriding social policy objective is improving social mobility, reducing social segregation; making sure what counts in our society are ability and drive, not privilege and good connections. Free schools will only be acceptable to me and my party so long as they promote those goals."
On admissions policy, he will insist that measures are being taken to ensure disadvantaged pupils get into free schools and academies. "We are also taking unprecedented steps to make sure disadvantaged pupils actually get into these schools. The more of them the school takes, the more money it gets.That's a simple, but crucial, financial incentive.
"No one has reformed the admissions code like this for years. In future, these schools must do all they can to make sure that they have the same proportion of free school meals pupils as the local average – at least."
Ruling out any moves to privatisation or profit-making, he will say: "Let me reassure you: yes to greater diversity; yes to more choice for parents. But no to profit-seeking within our state-funded education sector."
Labour's education spokesman, Andy Burnham, last night hit out at rules which let free schools employ non-qualified teachers. "Michael Gove's 'anything goes' approach to school reform is a reckless gamble with standards and the life chances of our children.
"Parents should be secure in the knowledge that all publicly funded schools will employ teachers with relevant training and qualifications."